This invention features a transversal toothbrush with a manual grip handle or attached to a power machine to provide, respectively, manual or mechanical brushing of the teeth with improved effectiveness.
Known toothbrushes are composed of a body, a front face, and a handle. The brush body is approximately rectangular and has rows of 7 to 12 tufts of bristles aligned in the direction of the length of the brush body. This body is extended along the length on one small side by a handle; such brushes are then called longitudinal brushes. There are also toothbrushes having a circular brush body with a diameter on the order of 1 cm for special applications.
With such brushes, the brushing of the teeth is done primarily by large amplitude longitudinal push-and-pull movements from front to back according to the longitudinal direction of the brush parallel to the rows of teeth, perpendicular to the direction of the teeth, and therefore called longitudinal brushing.
The known longitudinal toothbrushes were obviously required because until now it was thought that the brushing should be done parallel to the rows of teeth with large amplitude back and forth movements, from the incisors to the molars, using the muscles of the arm which make the forearm turn at the elbow or by pivoting the whole arm at the shoulder through the action of the rotator muscles.
The toothbrush according to the invention runs counter to such evidence and habits with respect to the brushing of teeth. It is composed of an essentially rectangular brush body with a handle appreciably angled, preferably perpendicular to the longitudinal direction of the brush body. Although at first sight this new configuration would appear not to work well because of not reaching the back teeth, it allows effective brushing because it promotes a transversal brushing consisting of an up and down transversal movement perpendicular to the rows of teeth and parallel to the teeth and to their implantation.
This "transversal" brushing cleans the prominent parts, and also the interstices and recessed parts of the teeth where material tends to collect and become stuck. It also allows a better massaging action on the gingiva, with greater efficiency in eliminating tartar at the collum dentis.
Longitudinal brushing with known longitudinal brushes permits good cleaning of the prominent parts of the teeth, but is not very effective on the interstices and recessed parts of the teeth. With such brushes transversal brushing is also quite possible, but with little vigor because it consists of a somewhat unnatural oscillating movement obtained by the rotating action of the wrist, the muscles of which are not very precise, strong or efficacious for exercise of this type.
Advantageously, the brush according to the invention allows brushing to be done when the handle is held fully in the hand, not using an oscillating movement but rather by pushes and pulls produced by turning the arm on itself with the bent forearm remaining rigid, or by pivoting the whole arm around the shoulder using the rotator muscles. In this case the inside of the hand is facing the chest, the articulation of the wrist, the muscles of the forearm and arm exercise significant pressure on the brush and the transversal brushing is very vigorous in the reciprocating vertical movements. This hold on the handle is the only one that allows a natural, easy reciprocating vertical movement. For children, holding this brush with such a different handle becomes a game, resulting in better hygiene. Studies have shown that handicapped persons have greater facility in producing an up-and-down movement than horizontal pushes and pulls.
Several toothbrush models having the form of a capital T allow an up-and-down brushing of the teeth; the brush body is the top horizontal member and the handle is the vertical staff of the T.
Some models are fixed, such as those described in documents DE 3228946 and FR 2,583,963. The first document describes a straight brush body or curved in order to accommodate the concavity of the jaw. Document FR 2,583,963 shows a brush whose orientation is accomplished by deformation of the handle which must be manufactured from a material with appropriate mechanical properties, or from a flexible plastic material molded onto a metal insert. These two documents do not reflect that about one-third of the handle, starting from the brush body, must have a concave curve with respect to the face when the brush is in the cleaning position. The information from these documents only poses the problem of what the geometric invention should be without defining the materials and their geometric shape, the precise definition of which is not evident to a specialist. The solution to the problems of such type of brush is not indicated in order that the technical questions might be resolved.
In document WO 95/01113 the angular hold is obtained by a mushroom shaped pin with longitudinal thin strips that engage in a cavity of the handle. In documents DE 2427877 and FR 2,583,963 the blocking of rotation is effected only in two positions, one longitudinal and the other transversal. These three documents do not take into account the curvature of the handle in order to make transversal brushing possible without striking the chin. The numerous unsealed surfaces of the rotation systems are only so many niches for detritus and bacteria that are reintroduced into the mouth at the next brushing. Toothpaste can penetrate between these surfaces, and hardening there, can jam the system and considerably increase the wear of the friction parts, and thus the working life of the unit. Document FR 2,583,963 FIGS. 1, 5, 7, and document DT 24,27,877 FIGS. 3, 4, 5 show a handle the concave part of which corresponds only to the length of clearance of rotation of the brush body, which is clearly insufficient to clear the chin. The profile of the handle of document UK 2101476 is totally nonfunctional because the starting point of the handle comes up against the lips, hindering the brushing.
Document D 077,889 shows a brush with two transversal positions and two longitudinal positions where the male end of the handle dovetails into the brush body. Blocking-in-position is obtained by a system of balls and a spring placed in the brush body. This document does not take into account the necessary curve of the handle to allow it to clear the chin. This system also has the disadvantage that the blocking-in-position is not definitive and the brush body can separate from the handle in the mouth and can be swallowed or cause a more serious accident by obstruction of the upper respiratory tract.
The handles shown in this prior art only take into account the rotation of the brush body while completely ignoring the problem posed by the clearance of the chin.
In other models, the brush body is shown rotatable on the handle, in order to bring it back in line with the handle in a traditional front-to-back brushing of the teeth. U.S. Pat. No. 5,499,422 describes a brush the handle of which is blocked in position with respect to the brush body by an anti-friction washer pressed by a rivet between a surface of the handle and a surface of the brush body. Document GB 2,101,476 shows a system for blocking-in-position that is composed of sufficient friction or by an appropriate locking means, whether the handle is constituted by a groove and a spring joint or equivalent means, or the shaft is equipped with a spring to make the head interchangeable. In these documents the means for blocking-in-position are not precisely described. It is also said that the head is interchangeable, which involves the risk that the brush body would detach and be swallowed during use, and possibly the risk of a more serious accident through obstruction of the respiratory tract. The large surface area between the two opposite supports and the unprotected mechanism constitute a niche for detritus and bacteria that are not compatible with our standards of hygiene. In U.S. Pat. No. 4,020,521, the rotation of the brush body is blocked by recessed saw tooth grooves according to the generators of a cylindrical bar of the brush body cooperating with the complementary recessed grooves around the periphery of an aperture in the handle. To allow the inclusion of the larger diameter bar in the bore hole, the hole has a radial slot on the outside. In this patent, the mechanism has no means, during the use of the brush, to prevent the separation of the brush body and handle, thus producing a significant risk of swallowing the brush body as well as the risk of obstruction of the respiratory tract as well. The mechanism has no protection to isolate the detritus, bacteria and toothpaste. Moreover, in FIG. 1 of the patent, it can be seen that the end of the split handle when it is in the transversal position projects outside the brush body and butts against the top of the gingivae, making it impossible to use the brush in the transversal position.
According to the invention, the elasticity and mechanical strength designs of the brush have made it possible to select type DR 51 PBT food Nylon as material. The brush body is fixedly connected, on one of its large sides, to the curved handle the direction of which is approximately in a center plane of the brush body. The brush body should be long enough that its right and left ends reach the molars without the starting point of the curved handle uncomfortably deforming the corner of the mouth, and that the handle can, by a narrowing, take the longitudinal position and the transversal position.
According to another example of realization, the handle is movably mounted on the brush body. It pivots around an assembly and blocking means between the handle and the brush body fix the handle in the transversal and longitudinal positions.